Monoclonal antibodies in cancer therapy.

A review of the clinical trials of antibody based cancer therapies reveals that this approach can, in rare cases, induce complete remissions in individual patients with cancer. Since these trials have usually involved patients with large tumor masses, tumor cell inaccessibility is probably a major reason for the prevailing failures. Minimal residual disease, the stage when tumor cells are few and dispersed, should therefore be a more promising target for therapeutic antibodies. This hypothesis is supported by a prospective randomized trial on patients with resected Dukes C colorectal carcinoma that resulted in increased survival and prolonged recurrence-free intervals. Thus, in addition to strategies designed to produce more effective, human-derived reagents, efforts need to be concentrated on directing passive antibody therapy towards the appropriate target.